Environmentally Friendly Cows – Reducing our

environmental hoof print

Paul Boettcher1

Benjamin Henderson1

Mark Powell21Animal Production and Health Division, Food and Agriculture Organization of the UN

2U.S. Dairy Forage Research Center, U.S. Department of Agriculture-Agriculture Research Service

The Importance of Livestock

• Livestock and their production provide many benefits to humankind– Food security– Wealth generation and maintenance– Rural development– Cultural significance– Environmental services

Livestock and the Environment

• The importance of livestock is expected to increase in the future– World’s population 33% by 2050

• mostly in developing countries– Consumption of milk 62% and meat 76%

• Livestock can have negative impacts on the environment– Among top 2 to 3 sources of environmental

degradation

Impacts of Livestock Production• One-third of arable land is used for the

production of livestock feed• One-quarter of the ice-free terrestrial surface

is used for grazing• One-fifth of the Earth’s animal biomass is

livestock• Livestock produce up to 18% of GHG• Dairying contributes significantly to these

impacts

Impacts of Milk ProductionFive main areas of impact• Landscapes and soil• Water• Biodiversity• Non-renewable resources• Greenhouse gases

Type and scale of impacts depend on production system

Landscapes and Soil• Feed crop production has various negative

direct and indirect consequences– Soil compaction, erosion and flooding– Nutrient overload– Deforestation

• Pasturing can cause trampling and degradation• Intensification of production can diminish the

aesthetics of the countryside

Water• Majority of water used in feed crop production

– leaching of nutrients and agro-chemicals• In the dairy, water is used in many processes,

from cleaning and sanitation to cooling of cattle• Lactating cattle consume 40 – 70 litres/d• Nutrients from poorly managed manure can

seep into ground and surface water

Biodiversity• Selection for genetic improvement tends to

decrease genetic diversity both within and across breeds

• Feed production involves plant monoculture– decreases the biodiversity of wild fauna, flora and

soil micro-organisms• Poorly managed grazing can reduce the

species richness and ecosystem function of grasslands

Non-renewable Resources

• Feed crop production consumes fossil fuels– Crop tillage and harvesting– Fertilizers

• Animal housing and milk collection and cooling consumes electricity– 800 to 1200 kWh/cow/yr (US data)

Greenhouse Gases

• Cattle emit methane as a by-product of rumination

• Manure can release nitrous oxide and methane• Feed crop production releases carbon dioxide• The global dairy sector produces 4% of global

antrhopogenic GHG emissions– 2.4 kg CO2 per kg of fat/protein corrected milk

Shrinking the Hoof print• Two general approaches can be taken to

increase the environmental impact of dairying– Improving the system and production environment– Breeding a “greener” Holstein cow

• Involves enhanced resource usage– Energy– Water– Nutrients– Biodiversity– Greenhouse gases

The System: Crop Production• Many of the environmental impacts of dairying result

from feed crop production• Applying “good practices” will reduce impacts

– Soil testing and judicious fertilizer application• Soil, water, energy

– Proper application of herbicides and pesticides• Water and wild biodiversity

– Controlled irrigation• Water and soil

– Well-managed land use changes• Greenhouse gases, landscapes and wild biodiversity

System: The Dairy • Develop (and use) a nutrient management plan

– Assure adequate land mass for off-farm nutrients• Properly store and apply manure

– Reduce impacts on soil, water, wild biodivesity and greenhouse gases

• Take steps to reduce electricity usage– install high-efficiency milk cooling systems– properly maintain electrical equipment– use automatic controls for lighting and ventilation

• Recycle and reuse water

The System: The Cows• Increase production per cow

– Less resources used/methane produced for maintenance• Balance rations

– Nitrogen is generally overfed– Must be balanced with other nutrients

• Improve reproduction and health– Under-producing animals emit more GHG per unit of

output– Replacement heifers emit GHG for two years prior to

yielding outputs

Breeding a “Greener” Holstein

• Breeding and genetics are powerful tools with long-lasting effects

• Possible option to reduce environmental impact of individual cows and the Holstein breed

• Is it also a feasible option?

Opportunities in BreedingPossibilities for breeding are limited:• Direct impacts on landscapes, non-renewable resources

are largely on an herd-level, rather than an animal-by-animal basis

• Water consumption has a genetic component, but...– not well studied– correlated with milk yield– consumption by cattle is relatively insignificant

• This leaves within-species biodiversity, nutrients and GHG and as possible targets for breeding programmes and selection

Within-breed Diversity The Holstein has benefited from strong breed associations, pedigree and performance recording and artificial insemination

Within-breed Diversity

These tools allowed selection for a highly productive...

Within-breed Diversity

... and highly uniform animal

Within-breed Diversity• but some diversity is necessary to allow for continued selection and for optimal reproduction and fitness

Within-breed Biodiversity

• Interventions are possible within the sire selection and utilization programmes to achieve greater within-breed genetic diversity– more balanced use of sires with decreased genetic

relationships among them• Would likely require cooperation across

countries and breeding companies– contrary to short-term economic goals

Within-species Biodiversity• The high production of the Holstein has made it the

world’s most ubiquitous livestock breed – invaluable contribution to food security– reduced across-breed biodiversity

• Their superior genes are not being used optimally– often not adapted to the environment– cross-breeding is done haphazardly

• Capacity development is needed to improve breeding programmes– breeders’ associations and recording and evaluation systems– conservation and sustainable use of local breeds– genomics for identification of optimal hybrids

Within-species BiodiversityCountries reporting the presence of Holstein cattle

Source: FAO 2007

Within-species Biodiversity• The high production of the Holstein has made it the

world’s most ubiquitous livestock breed – invaluable contribution to food security– reduced across-breed biodiversity

• Their superior genes are not being used optimally– often not adapted to the environment– cross-breeding is done haphazardly

• Capacity development is needed to improve breeding programmes– breeders’ associations and recording and evaluation systems– conservation and sustainable use of local breeds– genomics for identification of optimal hybrids

Selection: Nutrients/NitrogenNitrogen utilization is nearly an “ideal” trait• Measurable

– Milk urea nitrogen (MUN) already routinely recorded• Variable

– wide differences exist among cattle• Genetically controlled

– moderately heritable (h2 = 0.20 to 0.40)– no antagonistic genetic correlations

• Economically important– protein supplementation is costly– MUN is related to “wasted” nitrogen

• may also reduce nitrous oxide emission

Selection: Methane Emission• Direct selection may be possible

– Situation less favorable than for MUN– not routinely or inexpensively recorded

• There are several favorable circumstances– preliminary results show genetic variation– various technologies allow measurement– there is strong political interest

• research support– genomics could yield more accurate selection

Obstacles to Direct Selection• Lack of economic drivers

– no penalties or incentives for GHG emission– overfeeding of protein is generally economical

• Inclusion in selection index would decrease genetic response for other traits

• Assessment of farm-by-farm differences in genetics of GHG production may be difficult– breed-wise selection goal– incentives for using superior sires

Alternative Approaches

• Indirect selection may be the best alternative

• Historical selection for production has already greatly decreased the environmental footprint of the Holstein cow

Relationship between milk production, feed efficiency and CH4 emissions

Knapp et al., 2010

Impacts of Improved Production

1944 2007

Cows, n 415,000 94,000

Methane, kg × 106 62 27

Nitrous oxide, kg × 103 412 230

Land, ha × 103 1705 162

Water, L × 109 10.76 3.79

Resources/waste per 1 billion kg of milk (US data)

(Capper et al., 2009)

Selection for Total Efficiency

• But increased production is not a “magic bullet”

• Reproductive fitness has decreased over time• Longevity has decreased• Both of these factors are associated with

greater GHG on a herd-wise basis• Fortunately, current selection indexes account

for these factors

Conclusions and Recommendations

• Action is required to decrease the present and future impacts of dairy production on the environment

• Interventions are needed for management of both the cow and her production system

• Current breeding goals are likely to continue to decrease GHG emissions per cow– Goals may change with new environmental policies– research is needed to facilitate selection and

establish economic values

Conclusions and Recommendations

• Holstein genetics has the potential to increase food security in developing countries while decreasing environmental impact

• HOWEVER – the genetics needs to match the environment– pure Holsteins in situations with good management for

intensive production– well-planned crossbreeding in less-suitable environments– capacity building in management, recording breeding and

breed associations– conservation of local genetic resources where warranted